Police cars block the entrance to Tiananmen Square, as smoke rises from a jeep that crashed into a crowd near the Forbidden City. Photograph: AFP/Getty Images

Five people were killed and dozens injured when a jeep ploughed through a crowd, crashed and caught fire in Tiananmen Square, central Beijing, the site of a bloody crackdown on pro-democracy protesters in 1989.

Police evacuated and sealed off the square, which lies across a broad thoroughfare from the main gate of the Forbidden City, soon after the vehicle crashed at around midday on Monday. A police officer at its north-east corner told a crowd of flustered tourists that there was an "activity" in the square and that it would be closed indefinitely.

Three people in the jeep, the driver and two passengers, died in the crash, according to Xinhua. A female tourist from the Philippines and a man from southern Guandgdong province were also killed.

Pictures of the crash were posted online but quickly deleted by censors. One showed the charred shell of a four-wheel drive vehicle engulfed in flames on the pavement between the square and the Forbidden City, below a large portrait of Mao Zedong. Another, taken at a distance, showed a plume of grey smoke rising above the high red walls of the historic imperial palace.

The state-run Global Times newspaper reported on Tuesday that Beijing police had sought information on two people from Xinjiang whom they identified as likely suspects in a "major case [that] had taken place on Monday".

It said the notice, sent late on Monday night to hotels in Beijing, asked management to pass on information on suspicious guests or vehicles who had visited since 1 October. It named two residents of Pishan and Shanshan counties as likely suspects and described a light-coloured SUV and four Xinjiang-issued licence plates. Zhu Yan, a contact person with the hotel supervision squad in the Beijing Police, confirmed that his team issued the notice but told Global Times he could not comment further. The north-western region has seen repeated outbreaks of violence, including vicious ethnic riots in 2009 that killed almost 200 in its capital, Urumqi, and at least two major fatal incidents this year.

There are long-running tensions between the state and the large Uighur Muslim population, with many in the community chafing at cultural and religious restrictions and some aspiring to independence.

Authorities have blamed separatist groups for stirring up trouble, but exiles and human right groups argue that the government has been too quick to identify violent incidents as the work of terrorists.

In 2009 three people from Xinjiang set themselves on fire in a car at Wangfujing, not far from Tiananmen. Authorities said they were protesting over a land seizure dispute.

A young European woman living in Beijing said she had witnessed the aftermath of the crash as she left a nearby underground station shortly after midday. "What I immediately saw was a man on the ground, in his mid-60s. He didn't look like he was from the city, quite rural, maybe," she said. "He was unconscious, potentially not alive any more, very pale and discoloured. His head and his upper body were in a pool of blood.

"A couple of metres further, there was a woman sitting on the ground who was conscious. She was bent over and clutching her left thigh, and I could see that she was bleeding a lot."

The woman, who did not witness the crash itself, said a fire engine, an ambulance and a police car had sped past her as she walked away from the square. "I walked on a bit, and then saw a civilian and a security guard rushing towards the unconscious man on the ground," she said. "It looked like the civilian man was crying. He was really distressed."

Tiananmen Square has been one of China's most politically sensitive locations since 4 June 1989, when People's Liberation army soldiers fired on unarmed pro-democracy protesters, killing hundreds of people.

The square, now a popular tourist site, is dotted with security cameras and closely watched by scattered crowds of uniformed and plainclothes security agents.

Two reporters from AFP were detained on the scene "with images deleted from their digital equipment", the newswire reported. A BBC team was also briefly detained, according to a tweet by one of the corporation's reporters.

Within minutes of the crash, authorities erected high blue and green barriers around the site and temporarily blocked roads to the square. Transport authorities said that the underground station on Tiananmen's east side had also been closed.

By late afternoon the wreckage had been cleared and parts of the square reopened.